text: Tian et al. listed several criteria to assess a foam in a heat exchanger. The comparison of thermal-performance metal foams with materials conventionally used in the intensification of exchange (fins, coupled surfaces, bead bed) first shows that the pressure losses caused by foams are much more important than with conventional fins, yet are significantly lower than those of beads. The exchange coefficients are close to beds and ball and well above the blades.
  Foams offer other thermophysical and mechanical features:
  * Very low mass (density 5–25% of the bulk solid depending on the manufacturing method)
  * Large exchange surface (250–10000 m/m)
  * Relatively high permeability
  * Relatively high effective thermal conductivities (5–30 W/(mK))
  * Good resistance to thermal shocks, high pressures, high temperatures, moisture, wear and thermal cycling
  * Good absorption of mechanical shock and sound
  * Pore size and porosity can be controlled by the manufacturer
  Commercialization of foam-based compact heat exchangers, heat sinks and shock absorbers is limited due to the high cost of foam replications. Their long-term resistance to fouling, corrosion and erosion are insufficiently characterized. From a manufacturing standpoint, the transition to foam technology requires new production and assembly techniques and heat exchanger design.
  Kisitu et al.  pioneered the experimental investigation of using compressed copper foam for advanced two-phase cooling for high heat flux electronics. The metallic foam samples are designed and manufactured by a US-based company, ERG Aerospace Corporation. Heat fluxes as high as 174 W/cm2 were tested/handled. Data reveal that compressing the foam by four times in the streamwise direction (4X) enhanced thermal performance by more than 3 times, compared to the uncompressed metal foam. This was attributed to the fact that compressing foam proportionally reduces the effective hydraulic diameter and increases both the surface area per unit volume and foam bulk thermal conductivity, which all improve two-phase cooling performance. In addition, results show that compressed foam has a potential to increase the critical heat flux (CHF), which is pivotal in the safe operation of two-phase cooling at high heat densities. Preliminarly results show that compressed metallic foams can solve several issues faced with microchannels, including clogging, flow instabilities, low CHF, and others. As such, compressed foams are being proposed as new powerful alternatives to microchannels in pumped two-phase cooling for high heat flux electronics cooling/thermal management, including high performance computers, aerospace, military and defence, and power electronics.